Conventionally, Liquid Crystal Displays (LCDs) require many different voltages to drive various components within the display, including the LCD glass itself. DC voltages are needed to drive various DC elements while an AC source is needed to drive AC elements within the LCD device.
To meet the LCD's DC voltage need, multiple and different voltages must be supplied to various components within the LCD device. Multi-tap transformers are sometimes used to generate these varying DC voltages. Linear regulators can be also employed to step down the source voltage to the different voltages. However, in battery driven LCD devices, at least one required DC voltage often exceeds the battery voltage. As this voltage requirement is outside the range of the input battery, a switching power supply is also required in addition to the aforementioned linear regulators.
An AC voltage source typically drives cold cathode fluorescent lamps (CCFL). These lamps backlight the LCD display and also require a large AC voltage from the AC voltage source for operation. To meet this need, the AC voltage source is also often times larger than the input battery source. Accordingly, to generate the high AC output, many LCD system manufacturers employ oscillator circuits to generate the high AC voltage.
Although the above described design addresses the requisite DC and AC voltage needs for a battery driven LCD display, drawbacks exist. Specifically, with the conventional system, numerous components must be incorporated into the system to provide the needed multitude of diverse voltage sources. These additional components drive up the cost of the overall LCD system. Additionally, as LCD display systems are commonly used in size-limited micro-components, the additional elements inhibit the micro-device's goal of size reduction. The present invention is developed in light of these and other drawbacks.